1. Field of the Invention
This invention relates to lubricating means and in particular to means for lubricating the bearings journaling a shaft, such as that of an electric motor.
2. Description of the Background Art
In one form of conventional electric motor, the motor shaft is journaled on suitable bearings carried within the housing of the motor. Means are provided for lubricating the bearings and conventionally include means defining a lubricant reservoir and means for slinging oil or lubricant outwardly as a result of rotation of the motor shaft onto the bearings for continual lubricant circulation thereto. Such lubricant throwing means conventionally comprise lubricant slingers, whch may be mounted to the shaft for rotation therewith.
A problem arises in the use of such motors in atmospheres or environments where lint is present. Such an atmosphere, for example, is found in clothes dryer apparatuses.
In such atmospheres, lint tends to collect on the housing surrounding the motor shaft. It has been found that this collection of lint tends to build up over a period of time and, as a result of the rotary motion of the shaft, forms a wick which may extend from the exposed surface inwardly through the shaft opening and into the motor bearing oil reservoir. The wick thusly formed tends to conduct lubricant from the reservoir outwardly from the housing, thereby depleting the oil and causing failure of the motor bearings.
A number of attempts have been made to solve this vexatious and longstanding problem. Thus, illustratively, Doran D. Hershberger shows, in U.S. Pat. No. 3,855,489, an electric motor having a lint collar secured to the motor shaft in radial alignment within a portion of the end cap of the motor. As seen in each of FIGS. 2, 4, 5 and 6, the different embodiments of the Hershberger collar are adapted to be disposed radially inwardly of the inner edge of the housing opening 45 so as to cause lint that might collect on the shaft 20 between the pulleys 74 and guard 50 to be "inhibited from gaining entry into the bearing housing 34". In another form of seal for protecting bearings against the entry of detritus, such as in earthworking operations, William D. Coski discloses, in U.S. Pat. No. 3,835,933, the use of a plate for covering a sector of the outermost portion of the clearance space between an earth cutter and the shaft thereof. The plate engages an external portion of at least the cutter most adjacent to the clearance space. Means are provided for mounting the plate to the fixed shaft support bracket of the device.
In U.S. Pat. No. 1,557,191 of Ross Biddle, a spindle lubricator is illustrated wherein a button is provided with a knife edge scraping against a front surface of a gear to remove lubricant therefrom and permit the lubricant to flow onto a shelf extending from adjacent the gear to an annular groove on the inner surface of a bearing of the apparatus.
George R. Bott discloses, in U.S. Pat. No. 1,639,684, a dust excluding means including a series of annular plates, each of which has a hub extension so as to space the plates from each other on the shaft. Split washers are provided between the plates. The washers are of somewhat greater diameter than the internal diameter of the inner wall of the bearings and closing casing, but are diametrically contractable as a result of being split so that they are adapted to have a hugging frictional engagement with the outer edges of the wall.
Glenn H. Caley shows, in U.S. Pat. No. 2,073,830, a cleaning pad which is arranged to clean the commutator of an electric motor. The pad is carried by a resilient pressing means which is secured to the frame of the motor while permitting radial adjustment of the pressing means to vary the pressure of the pad on the commutator. The securing means further is arranged to permit rotation of the pressing means about the axis of rotation to permit adjustment of the pad circumferentially of the commutator.
In U.S. Pat. No. 2,860,931, Moses E. Brooks shows, in FIG. 6 thereof, a wiper 27 which wipes off a cylindrical wiping surface having edges which function as slingers. The wiping device is a fingerlike, radially mounted element preferably formed of bronze, nylon or other low friction material supported on a stem slidable in a guide to be urged by a coil spring against the wiping surface. The wiper functions to remove from the wiping surface coolant and lubricant fluids leaking past a pair of seals associated therewith.